The present invention relates to gas lighters of the xe2x80x9croll and pressxe2x80x9d type, and more specifically to child resistant lighters.
Roll and press gas lighters of the type used for lighting cigarettes are well known. A lighter of this type has a gas reservoir, a gas regulation system including a valve open/close system lifted and closed by a lever, and a wheel ignition mechanism. The ignition mechanism preferably comprises a spark-wheel disposed midway between two thumb-wheels whose diameter is larger than the spark-wheel. The spark-wheel rubs frictionally against a flint when rotated, in order to project sparks above the opened burner and therefore to produce a flame.
It is important to prevent the use of such lighters by children under the age of 5 years. Since 1994, the US authorities have specified the test for whether a lighter is child resistant by the CPSC Rules and Regulations.
Many child resistant lighter mechanisms have been proposed. There are two broad techniques for child resistance. Most systems use a lever mechanism having two positions; one where the mechanism is prevented from working (the lighter cannot function properly), and a second where the mechanism is manipulated (by displacement, pivoting, etc) to a position where the lighter can function and produce a flame. The mechanism resets automatically to its original position after the lighter has been used. In the other type of mechanism, the unlocking system is in the wheel assembly area in order to minimize the time the user takes to learn how to operate it. Usually, these systems do not use purely mechanical interlocking means as described above, but rather involve properties or parts which make the operation difficult for children while still easy to operate by adults.
There are many examples of the latter type of system. There is, for instance, U.S. Pat. No. 5,096,414, Zellweger/Parnet, in which the thumb-wheels are freely rotatable relative to the spark-wheel and the user has to press on the wheel assembly hard enough for the pulp of their thumb to bulge down between the thumb-wheels and engage with the spark-wheel.
Similarly in U.S. Pat. No. 5,897,307 the shield is extended around the spark wheel of the lighter so that direct access to the spark wheel to rotate it to operate the lighter is difficult, whereas operation of the lighter is possible by normal use by an adult by means of the pulp of the users thumb extending between the sides of the shield member to contact the spark wheel.
However both of these two types of lighter require the user to grip the spark wheel itself which can be uncomfortable and cause dirt to adhere to the users thumb.
WO-A-99/46539 discloses a lighter with an ignition resistance button B which is biased upwardly by a spring S and which hinders the child""s ability to engage the lever by means of the spring force provided by the spring S. This lighter has the disadvantage that some adult users may have difficulty providing sufficient force to depress the resistance button if the spring force is too great. Also some children may have sufficient strength to operate the lighter and also use different methods of igniting the lighter by sliding the head of the lighter against a surface of a table of floor which would enable a child to apply sufficient force against the resistance button B to ignite the lighter.
These and other systems are costly to manufacture and/or can too readily catch the eyes of children and induce them to try to find the trick of operating them too easily.
The object of the present invention is to provide an improved gas lighter which alleviates or overcomes these problems.
It is also an object of the present invention to provide an effective child resistant lighter which can be manufactured cheaply in large volumes.
Accordingly the present invention provides a child resistant lighter of the roll and press type, having a lighter body and an operating lever including an operating end and pivoted beneath a spark wheel assembly, the operating end of the lever being depressible by a digit of a user to operate the lever to release the gas required to ignite the lighter, characterized in that the said operating end is adjacent to a fixed impeding member, the said impeding member impeding the user""s digit in depressing the said operating end.
According to a further aspect of the invention, a child resistant lighter of the roll and press type is provided, having a lighter body and an operating lever including an operating end and pivoted beneath a spark wheel assembly, and having a compensating spring arranged at the valve end of the lever, characterized in that the required movement of a user""s digit in operating the said operating end is impeded by an impeding member, the operating end of the lever and the impeding member being so mutually arranged that the lever may be depressed to a first extent without the user""s digit being impeded by the impeding member, without causing the gas to be released.
According to a further aspect of the invention, a child resistant lighter of the roll and press type is provided, having a lighter body and an operating lever including an operating end and pivoted beneath a wheel assembly, characterized in that the lighter body forms a wall which extends upwardly and surrounds the operating end of the lever, thereby partially enclosing the lever so as to impede the required movement of a user""s digit in operating the operating end.
Preferably the impeding member is fixed with respect to the body of the lighter. The impeding member may surround the operating end of the lever.
Preferably the operating end of the lever is depressed by deformation of a users digit.
Preferably the impeding member extends to a level which corresponds approximately to the plane of the operating surface of the lever.
Preferably the lighter comprises a compensating spring arranged at the valve end of the lever to maintain the burner/valve closed, and that such that the impeding member and the operating end of the lever are so mutually arranged that the lever may be depressed to a first extent without being impeded by the impeding member, without causing the burner/valve to open, and depression of the lever to a subsequent extent is impeded by the impeding member and is achievable only by deformation of an adult user""s digit.
The result is a child resistant lighter which can conveniently be operated which requires no significant learning effort on the part of the user, in which the possibility of inadvertent ignition other than by the correct specified method is small, and which is relatively cheap and easy to manufacture.